Elektronenspektren p-donator-substituierter Benzonitrile und Benzoesäureäthylester/ Electronic Spectra of p-Donor Substituted Benionitriles and Ethylbenzoates

1983 ◽  
Vol 38 (3) ◽  
pp. 368-377 ◽  
Author(s):  
Günter Wermuth

Abstract The positions of 1La and 1Lb type absorption bands as well as the fluorescence polarization and natural lifetime show that p-donor substituted benzonitriles emit from a 1Lb-state. On the other hand, the nature of the lowest excited state of p-substituted ethylbenzoates depends upon the kind of the donor. In case of a dialkylamino group as donor substituent the emission occurs from the 1La-state, in case of weeker donors, like methoxy, from the 1Lb-state. In the intermediate case of p-aminoethylbenzoate the excited state depends upon the polarity of the solvent.The 1Lb← 1A transition occurs at higher wave numbers for the donor substituent ethylbenzoates than for the correspondingly substituted benzonitriles, although the ester group represents the stronger acceptor substituent than the nitrile group in spectroscopic respect. This effect is interpreted using perturbation theory according to Petruska.

2022 ◽  
Author(s):  
Subasri Mani ◽  
Gomathi Veu ◽  
Kavitha Mary Jackson

Abstract The present study was aimed to explore the characterization of polyhydroxy butrate extracted from the bacterial strain under optimized conditions for the production of bioplastic. Under optimized fermentation conditions, Polyhydroxy butrate (PHB) was extracted and subjected to examine their properties via Thin Layer Chromotogram (TLC), Gas Chromotogram- Mass Spectrometer (GC-MS), Fourier Transform Infrared spectrum (FTIR). The presence of a brown spot in the TLC plate indicates the presence of hydroxylgroup which is similar to the polymer group. GC-MS analysis of extracted PHB shows peaks at the retention time of 3.8, 11.6 which is corresponding to octadecanoic acid, hexadecanoic acid, butyl -2-ethylester confirms the presence of polymeric nature in the extracted PHB. The absorption bands of FTIR at 1719–1720 cm −1 indicate the presence of C=O group of PHB. The absorption peaks at wave numbers 500-1000 cm -1 , 1055 cm -1 and 1230 cm -1 denotes (OH) group, (C–O) stretch and (C=O) ester group. From these results, it was confirmed that the extracted PHB is having the potential to replace petroleum plastic.


2005 ◽  
Vol 59 (11) ◽  
pp. 1393-1398 ◽  
Author(s):  
Reikichi Iwamoto ◽  
Akishi Nara ◽  
Toshihiko Matsuda

In the present report we studied spectral characteristics of the near-infrared combination and overtone bands of CH vibrations of a CH sequence. The near-infrared bands of the CH in CHX3 (X, halogen), which were interpreted in terms of the CH stretching and CH deformation fundamentals without any ambiguity, typically showed how the frequency and intensity of a combination or an overtone depend on the vibrational excited state. In the CH–C–CH of CHX2CX2CHX2, the vibrations of one CH are isolated from those of the other CH, and the combination and overtone bands were similarly interpreted as those of the CH, although each of the combination bands was split into two because of non-degeneracy of the CH deformation. In the CH–CH of CHX2CHX2, the CH deformations only have coupled modes. The first combination showed four narrowly separate bands, which were reasonably interpreted on the basis of the CH stretching and the coupled CH deformation modes. We demonstrated that the first combination of coupled modes as well as the combination of up to, at least, the third order of isolated modes have the nature of the characteristic bands.


2014 ◽  
Vol 5 (3) ◽  
pp. 973-981 ◽  
Author(s):  
Prakash P. Neelakandan ◽  
Tarek A. Zeidan ◽  
Martin McCullagh ◽  
George C. Schatz ◽  
Josh Vura-Weis ◽  
...  

Ground and excited state spectra of co-facial PDI dimers embedded in DNA constructs depend on the geometry imposed by the construct.


2017 ◽  
Vol 146 (13) ◽  
pp. 134311
Author(s):  
Colin Harthcock ◽  
Jie Zhang ◽  
Wei Kong ◽  
Masaaki Mitsui ◽  
Yasuhiro Ohshima

1883 ◽  
Vol 36 (228-231) ◽  
pp. 285-286

After the reading of the note on chlorophyll at the meeting of the society on December 13th, I was reminded by Professor Stokes that e and others had succeeded in separating the complex to which the erm chlorophyll had previously been applied into two substances, or ather groups of substances, one characterised by its green colour and ed fluorescence, the other showing a more distinctly yellow colour without fluorescence, and he suggested to me that it would be advisable to ascertain whether the property of yielding glucose by decomposition with acids might not belong to one of these substances or groups of substances only. Professor Stokes at the same time kindly communicated to me the details of the process whereby he succeeded n effecting the separation referred to, a process depending on the action of carbon disulphide in' removing some of the bodies contained n an alcoholic solution of crude chlorophyll in preference to others. The process employed for the same purpose by Mr. Sorby is essentially the same. Before applying disulphide of carbon to an alcoholic extract of green leaves according to the process of Professor Stokes, it was necessary first to remove the ready-formed glucose, tannin, and other matters soluble in water, which almost always exist in such extracts, and which would by their presence have rendered the result of the experiment quite uncertain. This was done in the way I have already described. An ethereal solution of chlorophyll prepared by my method was evaporated, and the residue having been dissolved in alcohol, the solution was mixed with a quantity of carbon disulphide larger than the alcohol would dissolve, and the mixture well shaken. The carbon disulphide acquired a dark green colour, while the supernatant alcoholic liquid, containing principally the xanthophyll of Professor Stokes and Mr. Sorby, was yellow with a tinge of green. The two liquids having been separated, the lower dark green one was washed several times with alcohol to remove any of the xanthophyll that might still be present, and having then been mixed with a large quantity of alcohol, a current of air was passed through it to remove the excess of carbon disulphide as directed by Professor Stokes. In this way I obtained two liquids, one intensely green, the other deep yellow with only a tinge of green. The two liquids were found to contain substances essentially different so far as regards their products of decomposition with acids. The yellow liquid having been mixed with dilute sulphuric acid was evaporated in the waterbath, water being added during evaporation, until the liquid had lost nearly all its colour. A quantity of yellow fatty matter separated during evaporation, and this having been filtered off the liquid was found to contain an abundance of glucose. The yellow fatty matter insoluble in water, dissolved easily in alcohol, but the yellow solutio showed none of the characteristic absorption bands of “acid chloro phyll.” The dark green liquid, treated in exactly the same way yielded a dark green product insoluble in water. The filtrate Iron this gave a slight reaction with Fehling’s solution, but so trifling comparatively that I am inclined to attribute it to the presence o some substance not completely removed from the disulphide of carboi solution by washing with alcohol. The dark green product of tin action of acid insoluble in water was soluble, though with difficultyin boiling alcohol, the solution being dull green and showing the absorption bands due to “acid chlorophyll.” If, therefore, chloro phyll be defined as the constituent of the green parts of plants, which gives a spectrum showing the well-known bands at the red end, and yields by decomposition with acids the product or products going by the name of “acid chlorophyll,” of which Fremy’s phyllocyanin is the most important and most characteristic, then chlorophyll is not a glucoside. The glucoside which accompanies it and resembles it as regards solubility in various menstrua may have to be sought among the group of bodies to which the generic name of xanthophyll has been applied.


1986 ◽  
Vol 41 (11) ◽  
pp. 1311-1314 ◽  
Author(s):  
A. Balter ◽  
W. Nowak ◽  
P. Milart ◽  
J. Sepioł

Absorption and fluorescence properties, excited state lifetimes and fluorescence quantum yields were determined for a series of 3,5-diarylaminobenzene derivatives in solvents of different polarities. The role of the nitrile, methyl, phenyl and naphthyl substituents is discussed. Especially the steric effects on the spectroscopic behaviour of the investigated molecules are studied.


2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.


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